[TD-4001]<fix>: taosdemo restful segfault. (#5962)

* [TD-4001]<fix>: taosdemo restful segfault.

due to gethostbyname() is not thread-safe.

* fix uninitialized variable when invalid mode.
Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

src/kit/taosdemo/taosdemo.c

@@ -241,7 +241,7 @@ typedef struct SSuperTable_S {
   int8_t       autoCreateTable;         // 0: create sub table, 1: auto create sub table
   char         childTblPrefix[MAX_TB_NAME_SIZE];
   char         dataSource[MAX_TB_NAME_SIZE+1];  // rand_gen or sample
-  char         insertMode[MAX_TB_NAME_SIZE];    // taosc, restful
+  char         insertMode[MAX_TB_NAME_SIZE];    // taosc, rest
   int64_t      childTblLimit;
   int64_t      childTblOffset;
 
@@ -334,6 +334,8 @@ typedef struct SDataBase_S {
 typedef struct SDbs_S {
   char         cfgDir[MAX_FILE_NAME_LEN+1];
   char         host[MAX_HOSTNAME_SIZE];
+  struct sockaddr_in serv_addr;
+
   uint16_t     port;
   char         user[MAX_USERNAME_SIZE];
   char         password[MAX_PASSWORD_SIZE];
@@ -393,10 +395,11 @@ typedef struct SQueryMetaInfo_S {
   char         cfgDir[MAX_FILE_NAME_LEN+1];
   char         host[MAX_HOSTNAME_SIZE];
   uint16_t     port;
+  struct sockaddr_in serv_addr;
   char         user[MAX_USERNAME_SIZE];
   char         password[MAX_PASSWORD_SIZE];
   char         dbName[MAX_DB_NAME_SIZE+1];
-  char         queryMode[MAX_TB_NAME_SIZE];  // taosc, restful
+  char         queryMode[MAX_TB_NAME_SIZE];  // taosc, rest
 
   SpecifiedQueryInfo  specifiedQueryInfo;
   SuperQueryInfo    superQueryInfo;
@@ -1955,14 +1958,12 @@ static void printfQuerySystemInfo(TAOS * taos) {
   free(dbInfos);
 }
 
-static int postProceSql(char* host, uint16_t port, char* sqlstr)
+static int postProceSql(char *host, struct sockaddr_in *pServAddr, uint16_t port, char* sqlstr)
 {
     char *req_fmt = "POST %s HTTP/1.1\r\nHost: %s:%d\r\nAccept: */*\r\nAuthorization: Basic %s\r\nContent-Length: %d\r\nContent-Type: application/x-www-form-urlencoded\r\n\r\n%s";
 
     char *url = "/rest/sql";
 
-    struct hostent *server;
-    struct sockaddr_in serv_addr;
     int bytes, sent, received, req_str_len, resp_len;
     char *request_buf;
     char response_buf[RESP_BUF_LEN];
@@ -2011,27 +2012,7 @@ static int postProceSql(char* host, uint16_t port, char* sqlstr)
         ERROR_EXIT("ERROR opening socket");
     }
 
-    server = gethostbyname(host);
-    if (server == NULL) {
-        free(request_buf);
-        ERROR_EXIT("ERROR, no such host");
-    }
-
-    debugPrint("h_name: %s\nh_addretype: %s\nh_length: %d\n",
-            server->h_name,
-            (server->h_addrtype == AF_INET)?"ipv4":"ipv6",
-            server->h_length);
-
-    memset(&serv_addr, 0, sizeof(serv_addr));
-    serv_addr.sin_family = AF_INET;
-    serv_addr.sin_port = htons(rest_port);
-#ifdef WINDOWS
-    serv_addr.sin_addr.s_addr = inet_addr(host);
-#else
-    memcpy(&serv_addr.sin_addr.s_addr,server->h_addr,server->h_length);
-#endif
-
-    int retConn = connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr));
+    int retConn = connect(sockfd, (struct sockaddr *)pServAddr, sizeof(struct sockaddr));
     debugPrint("%s() LN%d connect() return %d\n", __func__, __LINE__, retConn);
     if (retConn < 0) {
         free(request_buf);
@@ -3724,7 +3705,7 @@ static bool getMetaFromInsertJsonFile(cJSON* root) {
         goto PARSE_OVER;
       }
 
-      cJSON *insertMode = cJSON_GetObjectItem(stbInfo, "insert_mode"); // taosc , restful
+      cJSON *insertMode = cJSON_GetObjectItem(stbInfo, "insert_mode"); // taosc , rest
       if (insertMode && insertMode->type == cJSON_String
               && insertMode->valuestring != NULL) {
         tstrncpy(g_Dbs.db[i].superTbls[j].insertMode,
@@ -4619,14 +4600,18 @@ static int64_t execInsert(threadInfo *pThreadInfo, char *buffer, int k)
   if (superTblInfo) {
     if (0 == strncasecmp(superTblInfo->insertMode, "taosc", strlen("taosc"))) {
       affectedRows = queryDbExec(pThreadInfo->taos, buffer, INSERT_TYPE, false);
-    } else {
-      if (0 != postProceSql(g_Dbs.host, g_Dbs.port, buffer)) {
+    } else if (0 == strncasecmp(superTblInfo->insertMode, "rest", strlen("rest"))) {
+      if (0 != postProceSql(g_Dbs.host, &g_Dbs.serv_addr, g_Dbs.port, buffer)) {
         affectedRows = -1;
         printf("========restful return fail, threadID[%d]\n",
             pThreadInfo->threadID);
       } else {
         affectedRows = k;
       }
+    } else {
+      errorPrint("%s() LN%d: unknown insert mode: %s\n",
+        __func__, __LINE__, superTblInfo->insertMode);
+      affectedRows = 0;
     }
   } else {
     affectedRows = queryDbExec(pThreadInfo->taos, buffer, INSERT_TYPE, false);
@@ -5425,6 +5410,32 @@ static void *asyncWrite(void *sarg) {
   return NULL;
 }
 
+static int convertHostToServAddr(char *host, uint16_t port, struct sockaddr_in *serv_addr)
+{
+  uint16_t rest_port = port + TSDB_PORT_HTTP;
+  struct hostent *server = gethostbyname(host);
+  if ((server == NULL) || (server->h_addr == NULL)) {
+    errorPrint("%s", "ERROR, no such host");
+    return -1;
+  }
+
+  debugPrint("h_name: %s\nh_addr=%p\nh_addretype: %s\nh_length: %d\n",
+            server->h_name,
+            server->h_addr,
+            (server->h_addrtype == AF_INET)?"ipv4":"ipv6",
+            server->h_length);
+
+  memset(serv_addr, 0, sizeof(struct sockaddr_in));
+  serv_addr->sin_family = AF_INET;
+  serv_addr->sin_port = htons(rest_port);
+#ifdef WINDOWS
+  serv_addr->sin_addr.s_addr = inet_addr(host);
+#else
+  memcpy(&(serv_addr->sin_addr.s_addr), server->h_addr, server->h_length);
+#endif
+  return 0;
+}
+
 static void startMultiThreadInsertData(int threads, char* db_name,
         char* precision,SSuperTable* superTblInfo) {
 
@@ -5588,6 +5599,12 @@ static void startMultiThreadInsertData(int threads, char* db_name,
     b = ntables % threads;
   }
 
+  if ((superTblInfo)
+      && (0 == strncasecmp(superTblInfo->insertMode, "rest", strlen("rest")))) {
+    if (convertHostToServAddr(g_Dbs.host, g_Dbs.port, &(g_Dbs.serv_addr)) != 0)
+      exit(-1);
+  }
+
   for (int i = 0; i < threads; i++) {
     threadInfo *t_info = infos + i;
     t_info->threadID = i;
@@ -5996,7 +6013,7 @@ static void *specifiedTableQuery(void *sarg) {
 
     st = taosGetTimestampMs();
 
-    if (0 == strncasecmp(g_queryInfo.queryMode, "taosc", 5)) {
+    if (0 == strncasecmp(g_queryInfo.queryMode, "taosc", strlen("taosc"))) {
       int64_t t1 = taosGetTimestampMs();
       char tmpFile[MAX_FILE_NAME_LEN*2] = {0};
       if (g_queryInfo.specifiedQueryInfo.result[pThreadInfo->querySeq][0] != 0) {
@@ -6009,9 +6026,9 @@ static void *specifiedTableQuery(void *sarg) {
       int64_t t2 = taosGetTimestampMs();
       printf("=[taosc] thread[%"PRId64"] complete one sql, Spent %10.3f s\n",
               taosGetSelfPthreadId(), (t2 - t1)/1000.0);
-    } else {
+    } else if (0 == strncasecmp(g_queryInfo.queryMode, "rest", strlen("rest"))) {
       int64_t t1 = taosGetTimestampMs();
-      int retCode = postProceSql(g_queryInfo.host,
+      int retCode = postProceSql(g_queryInfo.host, &(g_queryInfo.serv_addr),
               g_queryInfo.port,
               g_queryInfo.specifiedQueryInfo.sql[pThreadInfo->querySeq]);
       if (0 != retCode) {
@@ -6022,6 +6039,10 @@ static void *specifiedTableQuery(void *sarg) {
       printf("=[restful] thread[%"PRId64"] complete one sql, Spent %10.3f s\n",
               taosGetSelfPthreadId(), (t2 - t1)/1000.0);
 
+    } else {
+      errorPrint("%s() LN%d, unknown query mode: %s\n",
+        __func__, __LINE__, g_queryInfo.queryMode);
+      return NULL;
     }
     totalQueried ++;
     g_queryInfo.specifiedQueryInfo.totalQueried ++;
@@ -6171,6 +6192,12 @@ static int queryTestProcess() {
 
   printfQuerySystemInfo(taos);
 
+  if (0 == strncasecmp(g_queryInfo.queryMode, "rest", strlen("rest"))) {
+    if (convertHostToServAddr(
+        g_queryInfo.host, g_queryInfo.port, &g_queryInfo.serv_addr) != 0)
+      exit(-1);
+  }
+
   pthread_t  *pids  = NULL;
   threadInfo *infos = NULL;
   //==== create sub threads for query from specify table